Method pertaining to permanent waving of hair



Patented Aug. 13, 1929;

v' UNITED STATES PATENT OFFICE.

CHARLES NESSLEB, OF NEW YORK, N. Y.,'ASSIGNOR TO THE NESTLE-LEMUB COM- PANY, OF NEW YORK, N. Y., A CORPORATION OI OHIO.

METHOD PERTAINING TO PERMANENT WAITING OF HAIR.

I No Drawing.

This invention relates generally to methods and means for curling or wavmg ha1r and more particularly to growing halr on the head when it is to be given what is u ordinarily known as a permanent wave which is usually produced by dlviding the hair into strands and winding each on a suitable core or curling rod, the hair being treated with a lotion of alkali content and 1e subjected to heat, the lotion acting to soften the hair filaments while rolled up in a circular manner. While this art has'grown into a large industry, nevertheless hairdressers have gradually limited their practies to applyin the process only to such hair as appears toy e in sufficlently good physical conditionto undergo the process successfully, such limitation in their work being due to the many complaints of customers because of unsatisfactory results and actual damage I to their hair, the same processes would cause certain hair to shrivel up and become brlttle and harsh while certain other kinds could be waved over and over again without apparently showing any damage or inferior results from a hair-waving standpoint. 7

These drawbacks I have foundare due to the fact that the hair filaments of different heads have different structural characteristics'and that while the hair of one person will absorb liquid up to a certain percentage of the dry weight of the hair, that of another person will absorb a difierent percentage,

and further that the hair filament of loose structure will in some cases absorb ten times the amount of liquid as will be absorbed by hair of a tighter or tenser structure and that the looser the structure of the hair filament the less likely it is to be successfully waved by the prior processes, which invariably applied a lotion of uniform alkaline strength and such as to satisfactorily wave only the hair of the tightest or tensest structure.

I have discovered that extremely loosely constructed hair and hair that has lost some of its natural qualities by bleaching and much washing may take up liquid equal fully to its own weight, while tensely built and normal hair structures take up only ten per cent of liquid under the same conditions of immersion.

pacity of hair, or what I will term absorptivity, varies so greatly that out of many Indeed the liquid absorbing ca- Application filed January 13, 1927. Serial No. 160,995.

thousands of tested samples which I have catalogued, none in fact was found to be exactly like the other, so that my discoveries reveal the errors of the prior processes, which hmade no allowance for ab'sorptivity of the air.

I have discovered that the greater the liqmd absorbing capacity of the hair, the weaker should be the alkaline lotion used thereon; thus the full strength of the lotion should be used only on hair having the lowest absorptivity while the weakest lotion should be used on hair having the highest absorptivit y and in the same way the intermediate classes of hair should have their corresponding intermediate graduated strengths of llotion used thereon in accordance with their respective 'absorptivities.

After innumerable experiments and tests of various kinds in connection with hair filaments when treated with hot lotions particularly those containing alkaline hair-treat: ing substance, I have succeeded in definitely formulating classes of hair dependent upon their relative absorptivities and a series of graduated strengths of lotion corresponding in number to that of thehair. classes so for treating the same. I have also adopted a procedure in which the previously ascertained absorptiveness of a hair specimen serves to classify it and is utilized as the criterion which determines the strength of. lotion to be used in waving the hair; the number of hair classes and lotion grades being convenientlyfixed say for exampleat ten for the practical operation of my inventions, as hereinafter more full described.

My experiments also disclose t e fact that hair having from about 10 to 20 percentage absorptivity, constitutes less than 25 percent of the publics hair, so that heretofore about 75 percent of the subjects who had their hair permanently waved by the application of over-strong lotion, which should be used only on hair of low absorptivity, had reason to complain of unsatisfactory waving, whereas by apportioning the strength of 10- tion to absorptiveness I now succeed in successfully waving practically all kinds and conditions of hair.

I have found that the ca acity or power of the many different varieties of human hair to absorb liquid canbe definitely deter- "relative absorptivities only after numerous thorough and delicate ,tests of numberless samples of hair from different heads and the best results were secured by using a hot alkaline hair-treating solution of the type used in the actual Waving process and preferably of a strength below the medium.

As this method of ascertaining the relative absorptivity of hair is tedious and time taking and requires delicate weighing of the small hair-samples both in dry and wet conditions, after further and prolonged experiments I found that absorptivity is corelated to stretch or extensibility, the one being proportionate to the other, so that either of these factors may be used in place of the other in dealing with a porous substance like hair filaments. My experiments establish the fact that hair which absorbs the great est percentage of its'weight of liquid is capable of being stretched the greatest amount when pulled upon in wet condition with a given force, while hair which absorbs a lesser percentage of liquid will show less stretch or extensibility. For example, I took in each case a cut sample of the hair in strand form of suitable length and measured in cross-sectional area so that each had the same cross-sectional area or thickness. This I weighed dry, then soaked it for a given length of time, say 60 seconds, in an alkaline hair-treating lotion below m'edium grade, such for example as that which I grade as No. 6, and preferably at boiling point. The strand was then removed and shaken out and then immediately weighed wet to ascertain what percentage of the lotion was absorbed by it. Say for example that the. sample showed an absorption 'of about 100 percent. I then place it in a stretching machine. wherein a given length of the strand was pulled upon by a given amount of force for a given period of time, and it showed a 50 percent stretch, which is practicallv the extreme limit of stretch which hair is aptfto show. Since it showed practically the greatest absorptivity and greatest stretch I accordingly classed it as N o. 1, which I consider the loosest structure of filament and the least obstinate in physical character. On proceeding in the same way with numerous different varieties of hair, I found that hair whose absorptivity was say about 10 percent had a low percentage of stretch, say about 10 percent, and could be considered as of class N o. 10, of the series which I have adopted in practice. The intermediate varieties or grades of hair showed correspondingly intermediate percentages of absorptivity and stretch and furnish the intermediate classes of my group of 10 classes.

From my tests and experiments it is evident that knowing the approximate amount or percentage of stretch, the absorptivity of the hair can he arrived at by the data furnished by the stretching operation, so that the steps of weighing the sample dry and wet may be dispensed with. For this purpose, I have used with great success the type of hair-stretching machine disclosed in my pending application for U. S. Letters Patent, filed December 4, 1925, Serial No. 73,088. I have had machines like this for some time in daily use in the practical work of testing hair samples of the public which are sent to me to ascertain their absorptivities and to grade them accordingly as to class number and strength of lotion to be used in the waving process. If the sample falls in say class No. 7. the hairdresser knowingthis in advance will understand that he is to use lotion No. 7 the strength of which is best suited for the designated class of hair. Any customer once knowing the number of the class of her hair may have her hair subsequently waved by informing the hairdresser of the number and he may proceed accordingly.

In thus determining the absorbability of the hair I prefer to repeat the steps two or three times to obtain more definite data. I use as a standard a strand of the hairsample accurately measured in thickness in a special device so that in each instance it is 3/64 of an inch by 1/64, in a cross-sectional area. Then I immerse it for 10 seconds in a boiling alkaline hair-treating 10- tion of the waving type and reading about 2 Baum hydrometer. I then remove it and clamp it in the stretching machine leaving two-inches free betwcenthe clamping points for stretching action and it is kept warm while the pulling force is applied and which runs from zero gradually'up to 4: pounds which then a ts for 10 seconds, at the end of which time the reading of the stretch on a dial is noted. Then I remove it and repeat the stated steps but with the period of immersion increased to 60 second for absorption and at the end the second reading for stretch is taken. As a rule I repeat this second series of steps and take a third reading of stretch. With the three readings, one may better judge the approximate absorption, capacity of the hair sample and its elasticity.

In some cases a single stretching operation will substantially serve the purpose. The ascertained amount or percentage of stretch of the hair is taken as an approximate or substantial measure of the absorptivity thereof from which to determine its treatment with a weak or strong degree of the lotion, as the case may be. 7

For practical purposes, I find it suflices to have ten classes for relative hair stretching and absorptivities and ten variations in the strengths of the alkaline lotion graduated so that for example in waving hair of class No; 10, which is the least absorbent of liquid and stretches the least amount, lotion No. 10 should be used, for hair class No. 9, lotion .No. 9, should be used, and so on down the scale. Should for example the third reading of the stretch show about 17% of stretch or extensibility, I would class the hair as No. 10; up to 20% stretch,..., c lass No. 9; up to 25%. class No.8; .up to 30% stretch, class No. 7 up to 82% stretch, class No. 6; up to stretch, class No. 5; up to 37% stretch, class No. 4:; up to 40% stretch, class No. 3; up to stretch, class No. 2, and up to stretch, class No. l; the last two' named classes being high percentages do not occur often and are quite abnormal. This is a practical tabulation given as an example in carrying out the scheme which I have invented, but suitable variations may be made in it with the view of properly tempering or moderating the strength of the hair waving lotion in accordance with the ascertained porosity or ability of the hair to absorb liquid.

In the example given, hair-class No. 1, has the highest absorptivity and under the ratio devised by me, requires treatment with the weakest lotion, No. 1, and hair-class No. 10, has the lowest absorptivity and accordingly requires treatment with the strongest strength of lotion, No. 10; the intermediate hair-classes requiring the intermediate grades of strength of said lotion.

The well known hair-treating alkaline lotions heretofore employed in this art may be used with my improvements by adapting and regulating the strengths of the same in the manner herein described, but I do not recommend the use of borax. I prefer to use an alkaline lotion prepared from alkaline salts belonging to the sodium class dissolved in water and when the same is incor porated in dried fabric strips, a small quantity of suitable oil may be added also a small amount of adhesive or binder, the said substances being soluble in water when the strip is wetted therewith and squeezed out leaving practically no appreciable amount of solid residue.

In providing the progressively graduated strengths of lotion I prefer to have them vary about 10% between each number in order that the respective classes of hair in absorbing their assigned grades of lotion may receive substantially the same amount of the alkaline hair-treating substance in the waving process.

Any well known means may be used for graduating the set of lotions. of alkaline character as to their difl'erent required strengths, but I prefer to use the Baum hydrometer because of its accuracy and ease of operation. In this way the different grades are so adjusted by use of the Baum scale that the lotions whose respective specific gravities read by Baum from 1 to 10,.

have the corresponding series of ten numbers applied thereto so that No. 10 is defimtely known to apply to hair classed as No. 10, No. 9 to hair classed as No. 9 and, so on down the scale, i

The alkaline lotions may be put up in liquid form in bottles in the diiierent strengths, or in concentrated form with directions as to their use and the method of procurin the various strengths by adding neutral liquid such as water, but I prefer to make them up by means of pieces of absorbent material i1npregnated with the lotion and dried so that when immersed in a measured quantity. of water, say 1/10 of an ounce, the impregnated substance will dissolt e and produce a particular strength of hair waving lotion for application to a strand of hair. In marketing these strips, I put them up in a peculiar and novel manner whichforms the subjectmatter of another application for U. S patent, filed by me on even date herewith.

As most of the processes for permanent Waving of hair employ a degree of heat which reaches the boiling point of water, I therefore prefer to use in my preliminary tests for absorptivity, boiling alkaline lotion having substantially the same ingredients as that with which the hair is subsequently waved, so I am now able to know in advance to what extent the hair under treatment will absorb the heated lotion in the process, and also to observe any peculiar and unusual results from the advance use of the lotion.

I have further discovered that the treatment of hair by subjecting it to a boiling alkaline lotion, will often detect the presence of hair-dyes, iodine, bichloride of mercury and other mercurial preparations, as well as so-called hair-restorers containing lead, silver, etc. It is, of course, in'iportant'for the hairdresser to know these facts which are revealed in hair of light-color by a change of color to a darker shade after such boiling and the waving treatment can be modified to suit the condition of the hair at the time.

In the procedure ado )ted by me I am able to secure definite results by virtue of sev eral constant factors which enter into the same, such as a given cross-sectional area or thickness of the hair-sample; a given strength of testing lotion at a given temperature a given period of time for immersing the hairsample in the testing lot-ion; a given length,

I The ascertainment,

of the hair-sample subjected to stretching and a given amount of warmth applied thereto during stretching; a given amount of force applied in stretching; a given length of time for stretching, all of which factors are present during each performance of the series of steps herein described.

The procedure is so systematized that persons from all parts of the country send out hair-samples to iny laboratory where they are carefully tested for porosity and absorptiveness. They are then labeled with the number of the class in Which the hair falls also the number of the lotion which should be used in waving the hair and are then returned with this information.

By virtue of my improvements, the hairdresser may ascertain for himself the strength of the hair treating lotion to be used in waving a particular head of hair, by samplewaving a few strands of hair on the head each with a different number or strength of the lotion and then selecting the one showing the best results at the moment.

WVhile the amount of the stretch of the hair indicates its substantial absorptive capacity, it is evident that in testing the hair as hereinbefore described by observing the stretch thereof, it is not necessary to bear in mind that absorbtivity is thereby indicated; it being sufficient to note the extent of stretch and to employ, in the treatment of the hair, a corresponding lotion strength substantially in the ratio or propbortion herein described.

y observing the amount of stretch of the hair, of the proper lotionstrength to be employed is disclosed in my co-pending applications for patents, filed December 4th, 1925, Serial No. 73,087, and Serial No. 73,088, hereinbefore referred to, and the present application constitutes a continuation in part of each of said co-pending applications.

Having thus described my lnventlon, what I claim and desire to secure by Letters Patent is p 1. The method pertaining to the waving of hair, which consists in ascertaining the relative liquid absorbing capacity of the hair to be waved by subjecting a sample to a hot solution of the lotion to be used in wav ing the hair, then stretching it in wet condition and noting the amount of its stretch 1n percentage of its original length and using that as indicative of the relative liquid absorptivity of the hair and then applying to the hair a strength of solution regulated in accordance-with the determined absorptivity under the rule that hair of high absorptivity requires a weak strength of said lotion while hair of lower absorptivity requires 'a greater strength of lotion.

2. Ihe method pertaining to the waving of hair, which consists in ascertaining in advance the relative liquid absorptivity of the hair to be waved by subjecting a sample to a hot lotion of the type to be used in waving the hair, then stretching the wet sample of hair and noting its percentage of stretch in a given time with a given amount of force, then repeating said steps again or a third time and noting the percentage of stretch each time to perfect the data for determining the hairs absorptivity and then causing to be applied to the hair a lotion of a strength regulated in accordance with the determined absorptivity under the rule that hair of high absorptivity requires a weak strength of said lotion while hair of lower absorptivity requires a greater strength of lotion.

3. In the art of permanent hair waving, a series of graded hair-treating substances varying in strength in accordance with the varying capacities of hair in general to absorb liquid as manifested by their respective amounts of stretch when wetted and pulled upon by a given force, and said series of graded substances being adapted to be applied in sample-waving of different strands of hair on the head of a person to enable the operator to select and apply that strength best adapted for waving the particular hair under treatment.

4. In the herein described art of treating human hair, the steps of ascertaining as a factor in the hair waving process, the relative liquid absorptivities of the hair of dif ferent heads in general and sufiicient in number to provide a practical working series or range of absorptivities covering substantially their varying degrees of liquid absorptivities, and arranging a graded series of hair treating substance graduated as to strength from the weakest to the strongest and the number of such series of graduated strengths of said substance being equal to the number of the series of the varying absorptivities, then ascertaining the relative absorptivity of a sample of the hair to be waved in an individual or given case and using such absorptivity factor to determine which strength of the said graded hair treating substance to apply to the sampled hair in the process of waving it, a weak strength of the hair treating substance being applied to the hair of high degree of absorptivity and a greater strength of the hair treating substance being applied to the hair of a less degree of absorptivity.

5. In the method of treating human hair, subjecting the hair to a pulling action to ascertain its relative degree of stretch, and applying to the hair thus tested a hair treating substance having a strength regulated by the ascertained degree of stretch, a weak stren th of the hair treating substance being applied to the hair having a high degree of stretch and a greater strength of the hair treating substance being applied to the hair having a lower degree of stretch.

6. In the method of treating human hair,

lit

subjecting the hair to a pulling action in the presence of moisture to determine its degree of stretch, and applying to the hair thus tested a hair treat ng substance having a strength regulated by the determined degree of stretch, a weak strength of the hair treating substance being applied to the hair having a high-degrcie of stretch and a greater strength of the hair treating substance being applied to the hair having a lower degree of stretch.

7. In the method of treating human hair,

, subjecting the hair while wet to a pulling action in the presence of heat to determine its degree of stretch, and applying to the hair thus tested a hair treatlng substance having a strength regulated bythe ascertained degree of stretch,a weak strength of the hair treating substance being applied to the hair having a high degree of stretch and a greater strength of the hair treating substance being applied to the hair having a lower degree of stretch.

8. In the method of treating human hair,

' soakingthe hair in a liquid, subjecting the hair thus treated to a pulling action to determine its degree of stretch, and applyingto the hair thus tested a hair treating substance having a strength regulated by the ascertained degree of stretch, a weak strength of the hair treating substance being applied to the hair having a high degree of stretch and a greater strength of the hair treating substance being applied to the hair having a lower degree of stretch.

9. In the method of treating human hair, soaking the hair in a hot liquid, subjecting the hair thus treated to a pulling action to determine its degree of stretch, and applying to the hair thus tested a hair treating substance having a strength regulated by the ascertained degree of stretch, a weak strength of the hair treating substance being applied to the hair having a high degree of stretch and a greater strength of the hair treating substance being applied to the hair having a lower degree of stretch. I

10. In the method of treating human hair, testing the hair to ascertain its relative. degree of absorptivity and causing to be applied to the hair a hair treating substance,

aving a strength regulated by the ascertained degree of absorptivity, said hair treating substance being of a weak strength if the hair has a high degree of absorptivity and stronger if the hair has a lower degree of absorptivity.

11. In the method of waving human hair, grading in strength a hair treating substance in a series based upon the relative absorptivities of hair, testing the hair to be waved to determine the degree of absorptiv ity of the same, and selecting the hair treating substance of the series of graded strength so that the lllf er the degree of absorptivity lected, and applying such substance to the hair to be waved.

12. In the art of waving human hair,

the lower the strength of said substance seand a stronger strength being applied to the hair which stretches a smaller amount.

13. In the art of waving human hair, taking a strand of the hair to be waved of a certain cross sectional area, stretching a given portion thereof by pulling thereon with a given force for a given length of time and at-the expiration of said time noting the degree of stretch and taking that to determine the strength of the hair treating substance used in. waving the hair, the greater the degree of stretch of the hair strand the weaker the strength of the hair treating substance applied tothe hair in waving it and vice versa.

14. In the art of waving human hair, taking a strand. of the hair to be waved of a certain crosssectional area, immersing it in a liquid for a given time, then subjecting the hair strand to a given tensile pull for a given time and measuring the amount of stretch at the expiration of said time, and taking the ascertained amount of stretch as a factor to determine the strength of thev hair in waving it when the hair strand shows a a great amount of stretch and a stronger strength being used when the hair strand shows a smaller amount of stretch.

15. In the art of waving human hair, taking a strand of the hair to be waved of a certain cross sectional area, wetting the hair strand and then subjecting it to a given tensile pull for a given time, then releasing the pull and repeating said wetting and pulling of the hair strand one or more times and measuring the amount of stretch of the hair strand at the expiration of the time after each stretching and taking the several stretches as the factors to determine the strength of said hair treating substance used in waving the hair, the amount of stretch regulating the strength of said hair treating a stronger strength being used when the hair certain cross sectional area, immersing the hair strand in a hot'llquid for a given time then removing it from the liquid and subjecting it to a given tensile pull for a given time maintaining the hair strand warm durthe stretching thereof, and measuringthe amount of stretch at the expiration of said time, and" then taking the ascertained amount of stretch to regulate the strength of the hair treating substance applied in wavgree of stretch ing the hair a weak strength thereof being applied to the hair in waving it when the hair strand shows a great amount of stretch anda stronger strength being used when the hair strand shows a smaller amount of stretch.

'17. In the art of waving human hair, taking a strand of the hair to be waved of a certain cross sectional area, immersing for a given time the hair strand in a hot lotion bath having substantially the same ingredients as the lotion used in waving the hair of which the said strand is a sample and of substantially medium strength, then removing the hair strand from the bath and subjecting a certain portion of its length to a stretching action with a given force for a given length of time, keeping the hair strand warm during the strengthening operation, then noting the amount of stretch at the expiration of the said time, (and repeating or not the aforesaid steps), and then taking the ascertained amount of stretch as the element or elements determining and regulating the strength of the lotion applied to said hair in waving it under the rule that hair showing a high amount of stretch requires a weaker strength of said lotion than hair showing a lower amount of stretch.

18. Inthe herein described art of permanent waving of hair by application thereto of hair-treating substance and heat based upon the discovery that hair showing a high depossesses high absorptivity and requires a weak strength of said substance while hair showing a low degree of stretch possesses low absorptivity and requires a stronger stretch of said substance so that the absorptivity factor can be reckoned from that of stretch, the herein set forth step of ascertaining in advance the capacity or percentage of stretch of the hair to be waved by subjecting it to a stretching operation and thereby determining from its amount of stretch the substantial degree of strength of said substance required for that particular hair in waving it, the greater the amount of stretch the weaker the strength of said substance required, and vice versa.

19. In the herein described art of permanent waving of hair by application thereto of hair-treating substance and heat based upon the discovery that the hair of different heads varies n its capacity to stretch and that the'strength of said substance should-be varied accordingly and that hair having a high degree of stretch requires a low degree of strength of said substance while hair having a low degree of stretch requires a high degree of strength of said substance, the herein set forth steps of ascertaining as a factor the relative stretch of hair of different heads in general sufficient innumber to provide apractical working series or range of stretch covering substantially their varying degrees, arranging a graded series of said hair-treating substance graduated in strength from the weakest to the strongest and equal in number to the number of the series of stretch grades, then ascertaining the relative stretchrof the hair to be waved in a given case and using such stretch factor to determine which grade of strength of said substance should be applied to the hair in waving it, under the rule that hair showing a high degree of stretch requires a weaker strength of said substance than hair showing a low degree of stretch.

20. In the herein described art of permanent waving of hair by application thereto of'hair treating substance and heat based upon the discovery that the hair of different heads varies in its capacity to stretch and to absorb liquid and that the strength of said hair-treating substance should vary accordingly and that hair having a high degree of stretch possesses high absorptivity and requires a low degree of strength of said substancewhile hair having a low degree of stretch possesses low absorptivity and requires a high degree of strength of said substance so that' the stretch factor indicates that of absorptivity, the herein set forth steps of ascertaining as a factor the relative stretch of difi'erent heads of hair in general sufficient in number to provide a practical working series or range of stretch covering substantially their varying degrees, arranging a graded series of hair-treating substance graduated in strength from the weakest to the strongest and equal in number to the number of the series of stretch grades, then ascertaining the relative stretch of the hair to be waved in a given case and using such stretch factor to determine which strength of said substance should be applied to the hair in waving it, under the rule that hair showing a higlrdegree of stretch absorbs in a high degree and requires a weaker strength 1 of said substance than hair showinga low degree of stretch as it absorbs less.

21. In the method of waving human hair, causing to be applied to the hair a hair-treating substance having a strength regulated by the relative degree of the hairs absorptivity, said substance being of a weak strength if the hair has a high degree of absorptivity and stronger if the hair has a lower degree of absorptivity.

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22. In the method of waving human hair, causing to be applied to the hair a hairtreating substance having a strength regulated b thee-mount of the hairs stretch, said su stance being of a weak strength if the hair has a high. degree of stretch and stronger if the hair has a lower degreeof stretch.

23. In the herein described art of permanent waving of hair" by application thereto of hair-treating substance and heat based .upon the discovery that hair having, for example, a liquid absorptivity of substantially 100 per cent of its weight has also the highest factor of stretch and requires that said substance be of the weakest practical strength and hair having, for example, a liquid absorptivity of substantially 10 per cent possesses a lower factor of stretch and requires that said substance be of a greater strength and that the intermediate absorptivity percentages require that they be satisfied by said substance being proportioned accordingly in strength, giving substantially the amount or factor of stretch of the hair to be waved in a certain case, the step of applying the aforesaid rule by causing a weak strength of said substance to be applied to the hair in waving it when it shows a high degree of stretch and a greater strength when the hair shows a lower degree of stretch.

24. In the art of permanent waving or hair by application thereto of hair-treating supbstance based upon the discovery that hair having a high capacity for absorbing liquid should be treated with a weak strength of said substance while hair having a low absorbing capacity should be treated with a stronger strength of said substance and the intermediate absorbing capacities treated accordingly as to strength of said substance, the herein described steps of ascertaining in advance the relative absorptivity of the hair to be waved and determining from that the relative strength of said substance to be used, under the rule that hair showing high.

absorptivity re uires a weaker strength of said substance t an hair showing a low absorptivity, then verifying the said deduction thus obtained as to the strength of said substance, by sample-waving several strands of the hair to be waved by waving them each with a different strength of said substance including that strength previously determined from the ascertained absorptivity and strengths differing therefrom and noting the results for said verification.

25. The herein described method of treating hair on the basis of its relative absorptivity, which consistsin ascertaining its relative degree of absorptivity and deducing therefrom for its treatment the requisite strength of the hair-treating substance proportioned in strength in the ratio of a weak strength for hair having a high degree of absorptivity and a strong strength for hair having a low degree of absorptivity.

26. The herein described method of treating hair, which consists in proportioning 27. The herein described method of testing hair, which consists in determining the approximate absorbtivity of thehair by wetting a strand of the hair to be tested, then subjecting it to a predetermined degree of tension to stretch it, and noting the percentage of stretch under that degree of tension, the percentage of stretch being an approximate measure .of its absorptivity from which its class may be determined.

28. The herein described method of testing hair to determine its absorptivity class, which consists in dipping a sample of the hair in an alkaline liquid or lotion, then stretching the wet sample with a given force for a given length of time and at the end of said time noting the amount or percentage of stretch, this giving an ap roximat-e measure of the absorptivity of the ii repeated if desired.

29. The. herein described method o'fascertaining the relative absorptivity of hair,

0 air, from which it may be classified, said steps being which consists in wetting a sample of the hair with an alkaline lotion'of the sodium class of about 2 per cent strength bythe Baum hydrometer for about ten seconds, then subjecting, the wet sample for about ten seconds to a pulling forceof about four pounds, then at the end of said time noting the amount or percentage of stretch, from which the relative absorptivity of said hair may be determined.

30. The herein described method of ascertaining the approximate absorptivity of hair, which consists in wetting a strand of the hair to be tested of a definite crosssectional area, say about'3/64 by- 1 64 proximate measurenof the absorptivity of the hair.

31. The herein described method of as- I certaining the relative absorptivity of hair which consists in wetting a sample of the hair to be tested, then subjecting a strand of the wetted hair of a given cross-sectional area and for a given part of its length to a predetermined degree of tension'for a given length of time, and then at the end of said time noting the amount or percentage of stretch, this being an approximate measure of the absorptivity ofthe hair.

32. The herein described method, which consists in setting up or adopting a definite series of classes of hair classified in accordance with their different relative de- 10 gree of absorptivity and suflicient in number to practically cover the range of the different relative absorptivities of heads of hair in general, and setting up or adopting a definite series of different grades (at strength of substance for treating the hair and ranging from a weak grade to a strong one and corresponding in number to that of said hair classes for use in conjunction therewith, and then determining proportionately to the relative absorptivity of the hair to be treated, the grade of strength of said hair-treating substance requisite for treatment of said hair in the ratio of a weak grade of strength of said substance for hair having a high degree of absorptivity and a strong gradeof strength for hair having a low degree of absorptivity.

33. The herein described method, which consists in setting up or adopting a definite series of classes of hair classified in accordance with their different relative capacities to stretch and sufficient in number to practically cover the range of the different relative stretching capacities of heads of hair in general, and setting up or adopting a definite series of different grades of strength of substance for treating the hair and ranging from a weak grade to a strong one and cor responding in number to that of said hair classes for use in conjunction therewith, and

then determining proportionately to the relative stretching capacity of the hair to be treated, the grade strength of said hairtreating substance requisite for treatment of said hair in the ratio of a Weak grade of strength of said substance for hair a high stretching capacity and a strong grade of strength for hair having alow stretching capacity.

34. The herein described method, which consists in setting up or adopting a definite series of classes of hair classified in accordance with their different relative degrees of absorptivity and suiiicient in number to prao tically cover the range of the different relative absorptivities of heads of hair in general, and setting up or adopting a definite series of different grades of strength of sub stance for treating the hair and ranging from a weak grade to a strong one and varying progressively about ten percent in strength and corresponding in number to that of said hair classes for use in conjunction therewith, and then determining proportionately to the relative absorptivity of the hair to be treated,

the grade of strength of said hair-treatin substance requisite for treatment of said hair in the ratio of a weak grade of substance for hair having a high degree of ab sorptivity and a stron grade for hair having a low degree of a sorptivity.

35. The herein described method of treating hair, which consists in proportioning the and ascertaining the relative degree of ab-- sorptivity of said hair, and then determining from such ascertained absorptivity the said proportionate strength of said substance.

36. In the art of permanent waving of hair, the method which consists in employing a series of progressively graded strengths of hair-treating substance graded in accordance with the varying degrees of absorptivities of heads of hair in eneral, then determining the requisite gra e of said substance for treatment-of a given head of hair by selecting two or more different grades of strength of said substance, then ermanently waving two or more strands oi said given hair each with one of said selected grades of said substance, then observing the character of each of said waved strands, and then proceeding to permanently wave other portions of the head of hair by applying thereto that grade of strength of said substance giving the best results in said test waving of said two or more strands.

37. In the herein described art of permanent waving of hair by employing hairtreating substance and heat thereon based upon the discovery that hair having a high degree of stretch should be treated with a weak strength of said substance while hair having a low degree of stretch should be treated with a stronger strength of said substance, the herein set forth step of ascertaining in advance the capacity or amount of stretch of the hair to be waved by subjecting the hair to a stretching operation and determinin from its relative amount of stretch the substantial degree of strength of said substance required by that particular hair, the greater the amount of stretch the Weaker the strength of substance re quired, and vice versa.

38. In the method of determining the substantial strength of the hair-treating substance to be applied to particular hair in permanently waving the same, the steps in connection with said treatment of the hair, which consists in stretching a strand of said hair of certain cross-sectional area under a given tensile pull and measuring the distance it stretches, the hair being wetted and kept warm during the stretching thereof.

39. In the method of determining the substantial strength of the hair-treating sub stance to be applied to particular hair in permanently waving the same, the steps in connection with the treatment of said hair, which consist in stretching a strand of said hair of certain cross-sectional area under a given amount of pull and measuring the amount of the stretch.

40. In the method of determining the substantial strength of the hair-treating substance to be applied to particular hair in permanently Waving the same, the steps in connection with the treatment of said hair, which consist in taking a strand of said hair of given length or expanse and of certan cross-sectional area, pulling said length of the strand with a given tensile pull, and then measuring the distance of the stretch.

41. In the method of determining the substantial strength of the hair-treating substance to be applied to particular hair in permanently waving the same, the steps in connection with the treatment of said hair,

which consist in taking a strand of said hair of certain cross-sectional area, then softening the hair in a suitable manner to facilitate the stretchng thereof, then stretching said softened hair strand and measuring the amount of the stretch.

42. In the method of determining the substantial strength of the hair-treating substance to be applied to particular hair in permanently waving the same, the steps in connection With the treatment of said hair, which consist in taking a strand of said hair of certain cross-sectional area and stretching the same in wet condition, measuring the amount of the stretch, then softening said hair by placing it in a boiling lotion of certain alkaline strength, tlien re-stretching said ,hair in wet condition and measuring the amount of the re-stretch.

Signed at New York city, in the county of New York and State of New York, this 29th day of December, A. D. 1926.

CHARLES NESSLER. 

